1. Field of the Invention
The subject of this invention is the layout of a deoiler located at the end of the turbine shaft of a turbomachine.
2. Description of the Related Art
This type of deoiler (for which a description of a model is given in document EP 0 780 546 A) is placed at the exit from an airflow maintained in the machine to transport oil that lubricates bearings or other parts in order to separate air from the oil that is dispersed as a fog before air is released to the exterior, and to send oil to the inlet of the lubrication device. Recovery of oil prevents external pollution, drying of the lubrication circuit or even fire due to deposition on very hot external parts. The model of the deoiler considered herein comprises three main parts: a hub used for assembly and positioning of the deoiler on a vent shaft, concentric with the turbine shaft and projecting beyond the rear of the machine, and extending in front of the turbine shaft; a cover delimiting a housing with the hub; and a filter that may be a honeycomb network contained in the housing, held in place by the cover and responsible for separation of air and oil that is deposited on the walls of the honeycomb when the vent shaft drives the deoiler.
Document EP 0 780 546 A discloses a cover bolted to the hub to hold it in place, but the use of bolts makes the assembly heavier and complicates the assembly. Another solution is to weld the cover to the hub. This solution has the disadvantage that said cover is no longer removable.
Document FR 2 696 655 A discloses a layout in which the cover and a housing closing plate are provided with circular hubs, such that they can be slid onto the vent shaft one after the other. The cover is held in place axially by pins passing through its hub and the vent shaft, and by stop faces forming part of the turbine shaft and the closing plate. The closing plate appears to be held in place by a nut screwed onto the vent shaft. The layout is complicated.
In document FR 2 299 898 A, the hub and the cover are retained axially on the vent shaft between stop faces forming part of a bearing and a nut. The cover also stops in contact with a conical shoulder on the shaft. Once again, the layout is complicated since the vent shaft is required to act as a stop for each of the two elements of the deoiler and shaped accordingly.